Internal-combustion engine



Nov. 5, 1929. E. P. DuMANols INTERNAL COMBUSTION ENGINE oi'iginal FiledJune 1926 BY & W

AT TORN EYJ Patented Nov. 5, 1929 7 UNITED STATE EMILE PAUL DUMANOIS, OFBOULOGNE-SUR-SEINE, FRANCE, ASSIGNOR, BY MESNE ASSIGNMENTS, TO MAXMOORCORPORATION, OF NEW YORK, N. Y., A CORPORATION or DELAWAREETERNAL-COMBUSTION ENGINE Original application filed. June. 3, 1926,Serial No. 113,392, and in France May 17, 1926. Divided and thisapplication filed'J'uly 2, 1928. Serial No. 289,849.

This application is a division of application Serial No. 113,392, filedby me J une 3, 1926.

It is well known that the volumetric compression in internal combustionengines is limited by the so-called detonation, which is caused by anactual explosive Wave.

However, in order to provide for a high compression of the fuel mixtureaffording great advantages from an economical standpoint, substancescommonly termed antidotonating substances have been employed, acting bytheir chemical properties and serving to delay the formation of theexplosive Wave. But in view of the fact that this wave is of both aphysical and a chemical nature, I have cross-section of the conduit, thedetonation being replaced by a regular combustion after a. certain time,this may be followed anew by an explosive wave, if the section of theconduit remains constant or decreases.

It is further observed that, under similar conditions, an increase ofthe surface of the combustion chamber will produce a greater cooling ofthe gas, whereby the limit of compression at which the detonation takesplace, as well as the limit of self-ignition by compression, will be setback.

With the above observations as a basis, I have been enabled to provide acombustion chamber by which the desired object is attained.

For this purpose, the cross-section of the,

combustion chamber increases in the direction of propagation of theinflammation, and

the increase in the section may be continuous or intermittent; thesurface of the walls is relatively large, so as to obviate the explosivewave which tends to be produced, or to stop the propagation of suchwaves.

' tion.

The appended drawing shows by way of example, various embodiments of theinven- Figs. 1, 2 and 3 are respectively sections on the lines 11 ofFig. 2, and 2-2 of Fig. 3, and a front View of one embodiment,the-piston being shown at the upper deadv centre; and Fig. 4 is a frontView of a modification.

As shown at Figs. 1 to 4, the ignitor is disposed at 1 in the cylinder2, and, at its upper end, the piston 3 is formed with a head orprojecting part 4, whose upper face comes near the cylinder head whenthe piston is at the upper dead centre, as shown in the drawing. Thehead 4 is cut out to form a cylindrical recess 6 coextensive with thelength of the head 4, and extending in the direction of propagation ofthe inflammation. In the plane BB, the offsets 7 cause an abruptenlargement of the combustion chamber, both by the increase of.cross-section or width of the cylindrical recess 6 and by the loweringof the level of the upper face of the head 4, which proceeds from thepart 5 to the part 8. Like variations in the section of the cylindricalrecess and'in the lowering of the level of the upper face of the head 4takes place in the planes (f-C, DD, E-E, by the formation of transverseofisets 9, 10, 11 and vertical offsets 12,13,14.

The operation .is as follows:

Assuming that the piston is still raising, thus reducing the volume, andfacilitating the production of an explosive wave, the inflammationbeginning at 1 attains a point near the abruptly enlarged section BB,causing an expansion by which the velocity of the inflammation isretarded and the formation of an explosive wave is prevented. The sameis true when the inflammation reaches the section C-C, then the sectionDD, and finally the section EE.

From the foregoing it will be seen that the difl'erentoflsets formed inthe piston, starting from the point of ignition will produce. as theinflammation attains therespective ofi' sets, suitable expansions whichwill prevent the propagation of the explosive wave.

The above constructional details are given solely by way of example. Imay obtain the same effect, in other cases, by a construction in whichthe offsets at the top of the piston are eliminated or exist only upon acertain part of the head and on either side of the plane of symmetry, orin which the lower In the foregoing and also in the followingexplanations, I employ for the-sake of clearness, the term cylindricalto designate the outline of the successive recesses, but it should benoted that the invention is not restricted to cylindrical surfaces inthe geometrical sense of the word, but relates to surfaces of asubstantially cylindrical shape, or even to conical, spherical or likesurfaces, provided that the cross-sections are progressively larger inthe direction of propagation of the inflammation.

Moreover, the term ofl'set relates to regions of abrupt augmentation ofthe crosssection, but the walls may be either plane or curved, andsuitably inclined and connected together.

The number of offsets may be increased at will, either upon the whole orupon a part of the piston surface, in the direction of propagation ofthe flame, the whole or a part of the ofl'sets being thus replaced by acontinuous surface such that the cross-section is pro gressively larger.

In case the valves are laterally disposed or with engines with sleevevalves or engines of thetwo-stroke type, the ofl'sets or the surfacesconnecting two successive sections of increasing cross-section may beprovided solely upon the piston (as in the preceding case) or solelyupon the end of the cylinder, or both upon the end of the cylinder andthe end of the piston.

In the preceding construct ons, the ignitor is situated upon the sidewall of the cylinder. Arrangements based upon the same principle .may beprovided in case the ignition device is mounted on the cylinder head,for instance at the centre thereof.

When the engine comprises several ignitors, the increase in. thesections will take place (as above indicated) in the direction of proagation of the flame, starting from the di erent ignition points.

In the various embodiments hereinbefore described, I further obtain amaterial increase of the surface of the chamber in contact with the fuelmixture relatively to the constructions in current use, and hence anincreased cooling of the gas, by which the risk of deto nations andself-ignition by compression will be diminished.

I claim: 1. An internal combustion engine comprising opposing portionsforming a combustion ignition means.

chamber therebetween increasing in crosssection in a certain direction;certain of said portions having a channel centrally thereof extending inthe same direction, and facing the other of said portions, and ignitionmeans disposed in said combustion chamber adjacent to the moreconstricted portion thereof.

2. An internal combustion engine comprising opposing portions forming acombustionchambertherebetween increasing in cross s'ection from theignition pointvin the direction of propagation of the inflammation;certain of said portions having a channel centrally thereof increasingin width from said ignition point in the direction of propagation of theinflammation.

3. An internal combustion engine comprising opposing portions formingacombustion chamber-therebetween; certain of said portions having astepformation increasing in a certain direction in distance from theother of said portions, and having a channel centrally thereof extendingin the same direction and facing said other portion.

4;. An internal combustion engine comprising opposing portions forming acombustion chamber therebetween; certain of said portions having a stepformation increasing in a certain direction in distance from the otherof said portions, and having a channel cen trally thereof extending inthe same direction, and facing said other portion, and ignition meansdisposed in said combustion chamcombustion'chamber; certain of saidportions having a step formation increasing in dis- 05 tance from theother of said portions from the ignition point in the direction ofpropagation of the inflammation; and said ste formation having a channelcentrally thereo increasin in width in the same direction. I

6. An internal combustion engine comprising opposing portions forming acombustion chamber therebetween, ignition means in said combustionchamber;-certain of said portions having steps increasin in distancefrom the other of said portions rom the ignition point in the directionof propagation of the inflam i mation, and each step having horizontallateral' portions and concave recessed portions intermediate the same;said recessed portions increasing in width in the direction'ofpropagation of the inflammation; and the" riser portions of said stepsfacing towards the part of said combustion chamber remote from said 1257. An internal combustion engine comprising opposing portions forming acombustion chamber therebetween; certain of said portions including apart of step formation fac- 130 ing the other of said portions, andhaving a recess intermediate of the same.

8. An internal combustion engine comprising opposing portions forming acombustion chamber therebetween; certain ofsaid portions including partsof step formation facing the other of said portions, and having aflaring recess intermediate of the same.

9. An internal combustion engine comprising opposing portions forming acombustion chamber therebetween; certain of said portions includingparts of step formation facing the other of said portions, and having arecess intermediate of the same increasing in width towards one endthereof, and ignition means disposed adjacent to the more constrictedportion of said recess.

10. An internal combustion engine comprising a cylinder having acombustion cham her at the end thereof, means for supplying a fuelcharge thereto, and a plurality of terraced portions disposed within thespace between the piston portion and the wall portion of the combustionchamber opposite thereto, and projecting from one of said portionstowards the other thereof; said terraced portions being spaced toprovide a passage therebetween.

11. An internal combustion engine comprising opposing portions forming acombustion chamber therebetween; certain of said portions including apart of step formation extending towards the other of said portions andhaving an intermediate recess therein; said recessed part forming acombustion chamber portion increasing in cross-section in one direction,and ignition means disposed in said combustion chamber portion adjacentto the more constricted end thereof.

12. An internal combustion engine comprising opposing portions forming acombustion chamber therebetween; certain of said portions including apart of step formation extending, towards the other of said portions andhaving an intermediate recess therein of gradually increasingcross-section; said recessed part forming a combustion chamber portionincreasing in cross-section in one direction, and ignition meansdisposed in said combustion chamber portion adjacent-to the moreconstricted end thereof.

13. Aninternal combustion engine comprising a cylinder, a pistontherein, ignition means disposed laterally thereof, and projections onsaid piston decreasing in height from the ignition point in thedirection of propaga tion of the inflammation; said projections beingprovided with recesses increasing in width in'the same direction,whereby to provide a combustion chamber increasing in cross-section inthe direction of the propagation of the inflammation. Y

14. An internal combustion engine comprising a cylinder, a istontherein, ignition means disposed latera 1y thereof, and projections onsaid piston decreasing in height, from the ignition point in thedirection of propagation of the inflammation, and provided with recesseshaving an outline consisting of successive offsets.

15. An internal combustion engine comprising a cylinder, a pistontherein, ignition means disposed laterally thereof, and projections onsaid piston decreasing in height from the ignition point in thedirection of propagation ofthe inflammation, and provided with recesseshaving an outline consisting of successive lateral offsets.

16. An internal COl'IlbllStlOa engine comprising a cylinder, a pistontherein, ignition means associated therewith, and a portion of stepformation on said piston having a recess intermediate of. thesame.

17 An internal combustion engine comprising a cylinder, a pistontherein, ignition means associated therewith, and portions of stepformation on said piston having a channel intermediate of the samevarying in crosssection towards the end thereof.

In testimony whereof, I have signed my name hereto.

DUMANOIS, EMILE PAUL.

